1. Field of the Invention
The present invention relates to a half-fitting detection connector in which a half-fitted condition of two connectors can be detected. More particularly, the present invention relates to a half-fitting detection connector provided with a connection detection device which detects a half-fitted condition of the two connectors by detecting an electrical connection between connection detection contacts retained respectively in predetermined positions in the two connectors.
The present application is based on Japanese Patent Application No. Hei. 11-182037, which is incorporated herein by reference.
2. Description of the Related Art
Usually, various electronic equipments are mounted on a vehicle such as an automobile, and therefore, naturally, various types of female and male connectors are provided at connection ends of various kinds of wires forming wire harnesses or the like.
FIGS. 6 to 8 show a conventional half-fitting detection connector provided with a connection detection device for checking whether or not male and female connectors are completely fitted together.
This half-fitting detection connector 1 is disclosed in Unexamined Japanese Patent Publication No. Hei. 7-142122. When the amount of fitting of the pair of male and female connectors 3 and 4 relative to each other reaches a predetermined value, a lock projection 8 on an elastic lock arm 7, formed on a housing 13 of the male connector 3, is engaged in a retaining hole 11 in a housing 14 of the female connector 4, so that the pair of housings 13 and 14 are locked together in a connected condition, and also connection detection contacts (contact elements) 16 and 17, held respectively in predetermined corresponding positions in the male and female connectors 3 and 4, contact each other simultaneously when the engagement of the lock arm 7 is completed.
The male and female connectors 3 and 4 are multi-pole connectors each having a plurality of connection terminals received and retained therein at predetermined intervals. One of the plurality of connection terminals, retained in the housing 13, serves as the connection detection contact 16 whereas one of the plurality of connection terminals, retained in the housing 14, serves as the connection detection contact 17.
A resilient contact piece portion 16a of the connection detection contact 16 in the male connector 3 is connected at one end to the lock arm 7, and this contact piece portion 16a is displaced in accordance with the flexing (elastic deformation) of the lock arm 7.
When the fitting operation further proceeds from an initially-fitted condition (shown in FIG. 6) of the pair of male and female connectors 3 and 4, the lock arm 7 on the male connector 3 is flexed (elastically deformed) toward the housing 13 as shown in FIG. 7 until the amount of fitting of the two connectors relative to each other reaches a predetermined amount. In the flexed condition of the lock arm 7 during the fitting operation, the connection detection contacts 16 and 17 are kept out of contact with each other as shown in the drawings.
Then, when the amount of fitting of the male and female connectors 3 and 4 reaches the predetermined amount, the lock projection 8 on the lock arm 7 is fitted in the retaining hole 11 in the female connector 4 as shown in FIG. 8, so that the flexing of the lock arm 7 is canceled, and also the withdrawal of the lock arm 7 is prevented by the engagement of the lock projection 8 in the retaining hole 11. As a result, the housings 13 and 14 of the male and female connectors 3 and 4 are locked to each other in a mutually-fitted condition.
When the lock projection 8 on the lock arm 7 is thus engaged in the retaining hole 11 in the female connector 4, the flexing of the lock arm 7 is canceled, so that the connection detection contact 16 in the male connector 3 contacts the connection detection contact 17 in the female connector 4, and this electrical connection is detected by a detection electric circuit (not shown).
In the half-fitting detection connector 1 provided with the above connection detection device, all of the connection detection terminal 17 and the connection terminals 18 and 19, provided at the female connector 4, are plate-like tab terminals.
The normal connection terminals 20, provided at the male connector 3, are socket contacts, each having a socket portion 20a for fitting on the associated tab terminal when the two connectors are fitted together, whereas the connection detection contact 16 has the leaf spring-like, resilient contact piece portion 16a which is displaced in a direction of the thickness thereof in accordance with the flexing of the lock arm 7, and is pressed against the surface of the connection detection contact 17.
Therefore, for example, when a foreign matter 22 is deposited on the surface of the plate-like connection terminal 17, this foreign matter 22 is held between the resilient contact piece portion 16a of the connection detection contact 16 and the terminal 17, as shown in FIG. 9. Even when the fitting connection between the male and female connectors 3 and 4 is properly completed in this condition, the connection detection contacts 16 and 17 fail to be electrically connected together. Accordingly, since the detection electric circuit detects a non-electrically-connected condition, there is a possibility of erroneously judging the two connectors to be in a half-fitted condition.
Namely, in the above half-fitting detection connector 1, there is a possibility that the reliability of the connection detection device, comprising the connection detection contacts 16 and 17, is lowered, for example, by the intrusion of a foreign matter.